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v B. ARCHER.

MUFFLE FURNACE.

No. 430,414. PatentedJune 17, 1890'.

UNITED STATES PATENT OFFICE.

JOHN B. ARCHER, OF ASHINGTON, DISTRICT OF COLUMBIA.

MUFFLE-FURNACE.

SPECIFICATION forming part of Letters Patent No. 430,414, dated June 17,1890. Application filed January 30, 1390; Serial No. 338,551. (No model.)

To all whom it may concern.-

Be it known that I, JOHN B. ARCHER, a citizen of the United States, residing at VVashington, in the District of Columbia, have invented certain new and useful Improvements in Gas-Heated Muffle or Retort Furnaces; and I do hereby declare the following to be a full, clear, and exact description of the in:

vention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to certain new and usefulimprovements in gas-heated muflie and retort furnaces, whereby a plurality of -muffles or retorts may be subjected to the same and a constant degree of heat upon all their sides; and it consists in the combination of the several parts of which it is composed, as will be hereinafter more fully described and claimed.

Reference is had to the accompanying drawings, in which corresponding parts are designated by similar letters.

Figure l is a front perspective view of my invention applied to a muffle-furnace. Fig. 2 is a transverse vertical section on line 50 a; of Fig. 3 thereof. Fig. 3 is a longitudinal vertical section on line yy of Fig. 2. Fig. 4 is a front elevation thereof, showing the flue-connections, the main burners being removed.

The furnace structure A has a series of burners B on the forward end thereof, the burners opening into the horizontal combustion-passage a through the openings ct'cut in the wall thereof. The combustion-passage a has an arched floor a while the bottoms of the muffles O O and the tiles a and a constitute a top therefor, thus causing the passage to extend from endto end of the furnace, the muffles being supported on pillars X The muflles, which extend from side to side of the furnace, are placed at suitable distances apart and from the ends of the structure A, forming the vertical combustion-passages a and a, the former of which is connected with the rear end of the combustionpassage a. Between the two muffles and below the level of their tops an arch A is thrown from side to side of the furnace, and a tile a is placed between their bottoms, forming, as has been stated, a portion of the top of the horizontal.combustion-chamber. A roof formed of arches A abutting upon the end walls of the structure, and thetransverse arch A forms combustion-passages a7 overthe muffles, the passages being connected with each other through the arch A and with the vertical combustion-passagesa and a, the base of the latter of which is separated from the horizontal combustion-passage by the tile a, which also forms, as has been stated, a portion of the roof of passage a. DoWntake-flues D, entering the bottom of the passage a, carry the products of combustion into one end of the regenerative chamber D, under the arched floor a from the opposite end of which they escape through the escapeflue cl. Pipes E, through which air flows, enter the regenerative chamber D through the rear end thereof, and, passing through the front wall, are all connected with the distributing-pipe E from which distributingpipes F. lead to each burner, gas-pipes F entering the said distributing-pipes just before their entrance into the rear of the burners. As the flame from the main burners B may not be sufficient to maintain a proper temperature throughout the entire length of the combustion-passages, I place at the rear of the furnace and at the base of the vertical flue a a re-enforcer or burner B or a series of such burners, which are connected with the upwardly-directed openings a a tile 0 opening, in order to prevent the too rapid dis integration thereof by the high heat towhich it would otherwise be subjected. The burn ers B and B consist of a tile b let into the thickness of the furnace structure, having a central cavity Z)" therein, which is connected with the air-pipe E and gas-pipe E, and acts as a mixing-chamber. From their position and from the duty to which the tiles'are exposed they rapidly deteriorate, and for the purpose of making them readily removable and of substituting new ones I make them independent of the wall in which they are placed. It will be seen that the flame issuing from the burners B passes along the horizontal combustion-passage a, heating the bottom of themuffles, until, on arriving at the back of the furnace, it strikes the rounded being placed upon the muffle C opposite the deflecting-wall a by which it is directed upward through the vertical passage a where it is re-enforced by the flame from the burn er B, heating one side of the rear muffle, the unit-ed flame then sweeping over the top thereof and down the opposite side, through the passage a to the arch A, whence it rises, enveloping the rear side and top of the forward retort in a similar manner, and descends through the passage a heating the forward side of the retort, and, continuing to flow downward through the downtakes D, enters the forward end of the regenerative chamber-D, where it imparts its heat to the air contained in the pipes E, and from which chamber it escapes to the chimney by the escape-flue d. It will be seen that the top and bottom and both sides of the muffles are in contact with the flame that flows by them, the heat being maintained at all points within the furnace at the same approximate temperature by means of a pluralityof burners located at different points along the combustion-passage, and that the heat of the products of combustion, which would otherwise be lost, is utilized to heat the air-supply.

In the drawings I have shown two forms of muflles that may be employed. The one 0 is composed of flanged sections 0' of iron or steel plates, bolted together, a layer of ashestus being first placed between the contiguous flanges to render the joint impervious to gases, while webs c are formed upon the innor surface of the sections to prevent warping. The other retort O is composed of sections 0 of tile rabbeted together. If desired, a clay retort or muffle c of ordinary construction, may be inserted within the tiles 0 which then serve as protectors, preventing the flame from burning the inner retort, which is often costly, while the sections of tile may be readpipes may be provided and any suitable closure applied to the mouths of the retorts.

The arches A may be formed of wedgeshaped bricks f, held in position vby iron bands f.

Having thus described my invention, what I claim, and desire to secure by Letters Patent, is-

In a furnace, the combination of a plurality of muifles arranged within the furnace side by side, tiles placed between the bottoms thereof, forming a horizontal combustion-passage below the bottoms of the said muffles, an arch thrown between the two adjoining muffies below the levels of their tops, an arched roof abutting upon the end walls and upon the said arch, forming combustion-passages over the tops of the said muffles, a gas-burner in the horizontal passage, a vertical passage extending from the horizontal combustionpassage to the said combustion-passage over the muflles, and a re-enforce burner opening into the vertical combustion-passage, as and for the purposes described.

In testimony whereof I afiix my signature in presence of two witnesses.

JOHN B. ARCHER.

\Vitnesses: VERNON M. DORSEY, O. S. WHITMAN. 

